Timer



Apr. 24, 1923. 1,452,884

A. P. MCCULLOCH TIMER Filed Feb. 7, 1919 Patented Apr. 24, 1923.

1,452,884 P A TE N T OFF ICE.

UNITED STATES ALBERT P. -MCCULLOCH, OFDORCHESTER, MASSACHUSETTS.

TIMER.

Application filed February 7, 1919.

.To all whom z' t may concern:

Be known that I, AL T P. Mo- QUL oor-r, a citizenof the United States, residing at Dorehester, in the county of Suffolk and State of hflassachusetts, have invented certain new and useful Improveappertainsgto make and use the same,

The present invent-ion relates to improvements in I'timers, and more particularly to the small rotary timers employed in connection with automobile ignition systems.

A construction of timers generally employed consists of a metal housing within which is loeateda fibre -ring having a plurality of ,metahcontact plates received in the inner face tobe engaged bya contact roller which travels about Ithe inner periphery of the ring. This fibre ring as'normally constructed is provided withaseries of recesses to receivethecontactplates. The ring is furthermore provided with "a seriesof openings extending through it to receive the attaching members for securing the ring to the housing, and which actas conductors, conneeting the contact plates :with the usual terminal leadsr It is a matter of'some considerable diiiiculty .t-o satisfactorily form these rings, as .it is necessary to employ sev eral operations for completing them, and there is always a liability, especially when forming the recesses, of chipping off the ring andrendering it unfit for use.

One feature of the present invention is to improve the construction of timers of this character by providing a sectional ring, which may bemade accurately and at a comparatively small expense, and which in its completed form has certain advantages over the solid ring.

Another feature of the invention is to provide ,in a timer of this sort, having provision .for the injection of a lubricating medium at the upper portion of the housing, a clamping band within which the fibre ring is rigidly mounted, the clamping band extendin g about the outer periphery of the ring and being interposed between the ring and from working down between the --:.fihr.e ring and ,the wallofrthe housing Serial No. 275,639.

and causing deterioration of the ring, and is of extreme importance in conservingthe life of the timer.

Still further features of the invention consist in certain novel features of construction and combinations and arrangements of parts hereinafter described and claimed, theadvantages of which will be obvious to those skilled in the art from the following description.

In the accompanying drawings illustrating the preferred form of the invention, Figure 1 represents a. frontelevation,partly in section of the improved timer; Fig. 2 is a section of the timer housing on the line 2-2of Fig. 1 looking in the direct-ion of the arrows and having the shaft and rotating parts removed therefrom; Fig. 3 is a perspective view of one of the sections of the ring before its assembly; and Fig. 4 is a. perspective view of the band for clamping the various sect-ions of the ring together.

The timer shown in the illustrated em bodiment of the invention is a type used generally on Ford automobiles, and comprises essentially a metal housing 10 within which is supported an insulating ring 12. A series of contact plates 14 (4. in number) are received in the inner faceof the ring 12, and serve to complete an electric circuit through the usual contact roller 15. The roller 15 travels about the inner face of the ring 12, and to this end is mounted upona shaft 16 having a sleeve 17 secured thereto which carries a swinging ;arm '18 on the outer end of which the roller is journalcd. The roller is yieldingly maintained in con-- tact with the surface of the ring by a spring 20 interposed between the arm 18 and the sleeve 17, as shown in Fig. 1. Each of the contact plates 14 is provided with a terminal screw 22 which servesthe fdual function of binding the plate 1 1 and thering 12 to'the housing, and also as a conductor for the passage of current.

According to the usual construction. this fibre ring is made in one piece, having the recesses formed in the face to receive the contact plates 14, and it ,is a matter of 'consid-erable expense to form theserecesses accuratelyand without chipping the ring, so that they'may tightly hold the contact plates. As a matterof fact, the formation of the finished ring -in a" single-piece re- 1 ormed cutting dies. According to the pres -sections (4 in number) are assembled within cut invention, the expense of manufacturing the ring is materially lessened and the ring improved by making the latter in a plurality of separately formed sections which are later assembled to produce the finished ring. Each of these sections 25, as illustrated in Fig. 3, is provided with a shoulder 26 formed at each of the opposite ends, and serving to form a' complete recess for the reception of a contact plate when the sections are assembled end to end. These sections, owing to their configuration, may be molded accurately and cheaply in a single operation, without liability of weakening the ring, due to the cutting out of certain portions after it has been molded. These 2. metal clamping band 28 having inturned flanges 29 which are employed to grip opposite faces of the sections to retain the sections firmly and rigidly 1n assembled posi-.

tion. The clamping band is provided with a series of openings 30 with relation to which the sections are properly assembled,

and after the fibre ring has been mounted within the band, openings are bored through the ring in alignment with the openings 30 to receive the usual terminal screws 22. After the contact plates 14: have been seated within the corresponding recesses in the fibre ring, and the ring connected with the timer housing through the terminal screw, the inner face of the ring about which the roller 15 travels is turned down sufficiently to eliminate any shoulders at the junction of the contact plates 14 and the face of the ring and provide a continuous, smooth, circular track. As will be evident from an inspection of Figs. 1 and 2 of the drawings, each of the terminal screws 22 is provided with an insulating bushing 82 at the point where it passes through the clamping band 28 and the housing 10, in order to completely insulate the terminal screw from the housing.

The timer is normally positioned with the housing located as shown in Fig. 1, and in this position an oil duct 35 is located in the upper portion of the housing to lubricate the moving parts of the timer. It is found that this oil runs down the inclined wall 36 of the housing and enters between the fibre ring and the housing proper. This oil soaking into the ring may distort it and cause it to swell,making it impossible to keep the ring tightly secured within the housing. This distortion and loosening of the ring within the housing obviously interferes with the efficiency of the timer, as the roller 15 is thereby prevented from maintaining accurate contact with the inner surface of the ring at alltimes.- According to thefpresent invention the clamping band 28 is accurately fitted to the inside of the housthe flanges 29, rigidly grips the ring and ensures a close union between the ring and the housing. The band furthermore prevents oil or other lubricating medium from penetrating between the outer surface of the ring and the wall of the housing, and in this respect also contributes materially to the efficiency of the timer.

While it is preferred to employ the specific construction and arrangement of parts shown and described, it will be understood that this construction and arrangement is not essential except so far as specified in the claims, and may be changed or modified without departing from the broader features of the invention.

The invention having been described, what is claimed is:

1. A timer comprising a housing, a series of relatively thin contact plates, a fiber insulating ring of substantially greater depth than the thickness of the contact plates and consisting of a plurality of sections corresponding innumber to the plates and each having shouldered portions formed in the inner face at opposite ends to receive the contact plates when the sections of the ring are assembled therewith and provide a continuous, smooth, circular track, and terminal screws connected with the contact plates for securing the plates and insulating ring within the housing.

2. A timer comprising a housing, a fibre ring supported within the housing, a metal band gripping the outer peripheral surface of the fibre ring and accurately fitting the interior of the housing, and means for securing the ring to the housing.

3. A timer comprising a housing, a fibre ring, a metal band having inturned flanges to grip oppositefaces of the ring and adapted to fit closely within the housing, a plurality of contact plates received in the inner surface of the ring, and means passing through the contact plates for securing the meetingends of said sectors correspondingly grooved to receive the stems carried by said contacts, and each sector having a plurality of circumferentlal recesses for the embedding of said contacts.

ing, and this band, through the medium of 6. An insulating ring for ignition system:

comprising a plurality of arc-shaped sectors of insulating material and having circumferential recesses formed in the inner peripheral surfaces adjacent the ends, and 5 an annular metallic band Within which the sectors are clamped.

7 A timer comprising a housin I'ality 0 c ol arc-shaped sectors of lnsulatl a plung ma- 

